DE102007001098A1 - Process and plant for the production of steel - Google Patents

Abstract

The invention relates to a process for the production of steel and the recovery of slag containing a high content of additional elements such as vanadium in a two-stage process, wherein liquid pig iron is first blown at lower temperature to a high quality slag, which is processed separately after tapping while the pig iron is fed to at least one other converter in which or in which it will blow to steel at a higher temperature. It is intended to produce a high quality slag and shorten the production process for the steel. This is procedurally achieved in that the tapped from the first converter, metallic intermediate is subjected before the task in the second converter of a heating and / or holding phase.

Description

The The invention relates to a method and a plant for the production of Steel and slag with a high content of additional Elements such as vanadium in a two-stage process, the liquid Cast iron first at low temperature on a high quality slag blown which is processed separately after the tapping while the Pig iron is fed to at least one other converter, in which or at higher Temperature will blow to steel.

The Processing times in the first converter, where on the generation the high-grade slag is worked, are substantially shorter than for producing the steel in the second converter stage. Around to overcome this disadvantage without a wait to compensate for the different cycles must be recognized in practice in this second processing stage often used two converters.

One another problem to be considered must, is that the working temperature in the first stage at about 1400 ° C lies while in the steelmaking stage the temperature is around 1680 ° C.

While thus In a two-stage investment waiting times inevitably between The first, faster, and second stages occur for the Plant with two downstream converters for steelmaking one not complete Utilization of both converters of the second stage.

apart of it, of course, are for two converters in the second stage altogether higher Investment costs necessary.

According to the procedure finally, too still disadvantages with the system with only one converter per stage, because by the necessary waiting time before use in the second converter, So before it is free again, production losses and possibly also significant problems for the melt, because freezing on the transport vessel can not be avoided.

Of the Invention is therefore the object of a method and a To create facility that avoids the above disadvantages be on the one hand and a high-quality slag can be generated and on the other hand, the entire production process for the steel shortened can be.

Is solved this object according to the invention with a Process in which the liquid Cast iron first at low temperature on a high quality slag blown which is processed separately after tapping while the pig iron is fed to at least one other converter, in which or in which it at higher temperature to steel is blown, thereby, that from the first converter Tapped metallic intermediate before the task in the second converter subjected to a heating and / or warming phase becomes.

The Heating or keeping warm by dosed injection of Oxygen.

In terms of assets according to the invention for this purpose a heating station that uses an oxygen injector, such as an oxygen lance, is assigned.

With the method according to the invention On the one hand it is achieved that the cycle times between the bubbles in the first converter and the production of the pig iron in the second Converter, which runs much slower, no longer play a role, because this period can be bridged in the heating station.

By the feeding of oxygen, by means of a lance, becomes part of the in the metallic intermediate carbon burned. The injected amount of oxygen can now be dosed differently be, and that is the possibility only the temperature during to keep the waiting cycle, so the usually occurring temperature losses compensate.

on the other hand but also a larger amount of oxygen supplied become. This in turn ensures that the higher carbon emissions the blowing process in shortened the subsequent converter can be.

simultaneously but also by the higher Burning off the carbon raises the temperature of the melt so that the for the second blowing process higher temperature from about 1680 ° C already to the transfer can be adjusted to the second converter. This also shortens the treatment time at this second Blasstufe considerably.

By thus shortened overall Treatment time in the plant can significantly increase productivity be increased, with comparatively lower investment costs compared to one Plant with three converters and the restriction by the necessary Cycle compensation.

The Invention will be explained below with reference to the drawings.

In this shows:

1 schematically the procedure in a system according to the invention with a heating stand,

2 schematic heating stand,

3 a two-stage system according to the prior art with three converters and

4 a corresponding plant with two converters.

First, let's look at the 3 and 4 referenced, showing that the liquid pig iron first in the converter 1 will dazzle with the goal of achieving a high quality slag. The temperature is around 1400 ° C. After the slag has been tapped, which is then sent for refining, the intermediate metallic product, after a compulsory waiting break, becomes two converters 2 and 3 fed and blown there at about 1680 ° C to crude steel, which is then subjected to further treatment, for example in a vacuum system.

As mentioned above, in such a system with two downstream converters is often not sufficient capacity for this to achieve. This disadvantage occurs in the system 4 Not on, but here play the waiting times with which the blowing cycle of the first converter to the second converter must be adjusted, a significant - negative - role.

remedy creates here now the system according to the invention, in de a Heizstand is provided between the two converter stages.

The 2 shows schematically how this heating stand can look, using the example of a system with two receptacles for transport vessels. In the left-hand illustration, the transport vessel with the metallic intermediate product contained therein is in the blowing position, in which oxygen is supplied by a lance bw. Is blown. In the right-hand illustration, a transport vessel is shown, which can be closed with a lid.

Claims (5)

A process for producing steel and recovering slag containing a high content of additional elements such as vanadium in a two-stage process, wherein liquid pig iron is first blown at a lower temperature onto a high grade slag which is separately processed after tapping while the pig iron is fed to at least one other converter, in which or in which it is blown at higher temperature to steel, characterized in that the tapped from the first converter, metallic intermediate is subjected before the task in the second converter of a heating and / or holding phase , Method according to claim 1, characterized in that that the metallic intermediate during the holding phase by Blowing in oxygen is heated. Plant for implementation of the method according to one of the preceding claims, characterized by a first converter for blowing molten pig iron, at least another converter for receiving the from the first converter tapped, metallic intermediate and producing crude steel and a heating station between the first and the second converter, in which the transport of the metallic intermediate from first to the second converter accepting Transport vessel deductible is. Plant according to claim 3, characterized in that the heating stand is designed to accommodate a plurality of transport containers. Plant according to one of the preceding claims 3-4, characterized characterized in that in the heating stand means for blowing is provided by oxygen in the transport vessel.